export default function MP(ak) {
  return new Promise(function(resolve, reject) {
    window.onload = function() {
      resolve(BMap)
    }
    if (!window.BMap) {
      var script = document.createElement('script')
      script.type = "text/javascript"
      script.src = 'http://api.map.baidu.com/api?v=2.0&ak=' + ak + '&callback=init'
      script.onerror = reject
      document.head.appendChild(script)
    }
  })
}